In the world's most arid agricultural environments, jatropha is emerging as an alternative to ethanol

From China to Brazil, countries have begun setting aside tens of thousands of acres for the cultivation of jatropha – a plant many experts say is the most promising source for biodiesel. At the same time, companies from Europe and India have begun buying up land throughout Africa to establish jatropha plantations.

As American farmers plan to plant the most corn since World War II to cash in on ethanol, which is added to gasoline, much of the rest of the world is turning to jatropha, which is used as a substitute for diesel fuel.

jatropha is fast emerging as a candidate for the ideal biofuel. It is grown in wastelands, needs relatively little care or refinement, and is inedible – meaning it will not take food from the poor for the gas tanks of the rich.

takes little refinement: a hydraulic press to squeeze the oil from the seeds, and a chemical solution to create and filter the fuel.